Role of slow phase separation in assessing the equilibrium phase behaviour of PC-PMMA blends

This chapter summarizes the research related to thermal degradation of unstabilised polyvinyl chloride (PVC) at conditions characteristic of processing, i.e. low oxygen levels and temperatures up to 250°C. The presentation concentrates on recent work and covers the recent literature. In the relevant sections, special emphasis is given to our own findings.

Thermal Degradation of PVC

High pressure kinetics appears to be a valuable tool in investigating the mechanism of specific organic reactions. For instance, in pericyclic, Mentshutkin, cage, and polymerization reactions, such studies reveal various features of the transition state, in particular its localization along the reaction coordinate and its nature. However, precise conclusions require separation of the different effects (electrostatic, steric, orbital, etc.) which may contribute to the structure of the transition state.

High Pressure Kinetic Investigations in Organic and Macromolecular Chemistry

Pressure is an element in the control of natural phenomena, as is temperature. The investigation of the role of pressure must be understood so that we may control and use pressure effectively.

Polymerizations at High Pressures

Kinetische Untersuchungen bei hohen Drucken sind ein sehr nutzliches Verfahren zur Aufklarung des Mechanismus einer Vielfalt organischer Reaktionen. Sie geben beispielsweise bei pericyclischen, Mentshutkin-, Kafig- sowie Polymerisationsreaktionen Auskunft uber die Beschaffenheit und die Position des Ubergangszustands entlang der Reaktionskoordinate. Die Deutung der Ergebnisse setzt jedoch voraus, das verschiedene, die Struktur des Ubergangszustands bestimmende Effekte (elektrostatische, sterische, Orbitalbeitrage etc.) anteilmasig getrennt werden konnen.

G Talamini

Papers

Vinyl-chloride polymerization to 2 500 atm